I've read they need big tanks for groups but, from wetwebmedia, I've read that the fathead anthia is more like a hawkfish and would do fine alone in a 40 gallon.
Two different 'sailfin blennies'. The common one is the Atrosalarias fuscus, and the other (the one I'm getting) is the atlantic black sailfin blenny Emblemaria pandionis. My main concern with this blenny is it's ability to get along with a randall's shrimp goby. If it can't, I might try a different kind of swimming blenny in place of the goby.
Ok I was just checking. Lol. I wasnt sure if you meant sailfin blenny or sailfin tang lol.